Hookless rims are generally only suitable for low inflation pressures of about 35-40psi. Might be ok for big volume mtb tyres but not for tandem road tyres.
We’re touring at the moment on tubeless Schwalbe G-one Speed tyres and they are going great. Plenty of grip and they roll really well. Our wheels are custom layup Lightbicycle RG722 650b rims with CK tandem hubs and cx-ray spokes. We are most probably around the 175kg mark including bags, bottles etc.